As one example of an apparatus for ejecting a liquid material with advancing/retracting movements of a plunger which slides along an inner surface of a pipe, there is known an apparatus comprising a liquid material reservoir for storing the liquid material, a nozzle portion for ejecting the liquid material, a liquid feed channel for communicating the reservoir and the nozzle portion with each other, a plunger portion having a seal portion sliding in close contact with an inner surface of the liquid feed channel, and plunger moving means for advancing and retracting the plunger portion, wherein the apparatus further comprises another liquid feed channel for communicating part of the aforesaid liquid feed channel near its distal end on the nozzle side with part of the aforesaid liquid feed channel near the liquid material reservoir or with the liquid material reservoir, and a liquid feed valve disposed at the distal end of the aforesaid liquid feed channel or midway the aforesaid liquid feed channel. As an embodiment of the apparatus, an apparatus including an ejection valve (liquid feed valve) extending laterally with respect to the advancing/retracting direction of the plunger is illustrated (Patent Document 1).
Also, there is disclosed an apparatus comprising a pump portion for metering an ejected liquid material in a desired amount, a valve portion for selectively changing over liquid material channels for suction and discharge, a reservoir portion storing the liquid material and being able to communicate with the pump portion depending on a position of the valve portion, and an ejection portion provided with an ejection port through which the liquid material is ejected, wherein the pump portion and the valve portion are disposed successively in an adjacent relation. As an embodiment of the apparatus, the following arrangement is illustrated and described; namely, a valve block serving as one component of the valve portion is disposed on one lateral side of a cylinder block serving as one component of the pump portion, the cylinder block and the valve block are held in close contact with each other by causing the cylinder block to be pressed against and fixed to the valve block through a pushing member at a distal end of an air cylinder by the action of air pressure supplied from air control means, and the valve block is caused to slide in contact with the cylinder block by an air cylinder which is disposed on the backside of the valve block (Patent Document 2).
Thus, in order to obtain power necessary for operating the valve, it is required in the prior art to provide a valve driving source in layout extending laterally with respect to the advancing/retracting direction of the plunger as in Patent Document 1, or to provide it in a position opposing to the plunger with the valve interposed therebetween or on the backside of the valve as in Patent Document 2.
Patent Document 1: Japanese Patent Laid-Open No. 2003-126750
Patent Document 2: Japanese Patent Laid-Open No. 2001-227456